Chapter 13. Memory, Learning, and Development
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By Gretchen Reynolds Exercise seems to be good for the human brain, with many recent studies suggesting that regular exercise improves memory and thinking skills. But an interesting new study asks whether the apparent cognitive benefits from exercise are real or just a placebo effect — that is, if we think we will be “smarter” after exercise, do our brains respond accordingly? The answer has significant implications for any of us hoping to use exercise to keep our minds sharp throughout our lives. In experimental science, the best, most reliable studies randomly divide participants into two groups, one of which receives the drug or other treatment being studied and the other of which is given a placebo, similar in appearance to the drug, but not containing the active ingredient. Placebos are important, because they help scientists to control for people’s expectations. If people believe that a drug, for example, will lead to certain outcomes, their bodies may produce those results, even if the volunteers are taking a look-alike dummy pill. That’s the placebo effect, and its occurrence suggests that the drug or procedure under consideration isn’t as effective as it might seem to be; some of the work is being done by people’s expectations, not by the medicine. Recently, some scientists have begun to question whether the apparently beneficial effects of exercise on thinking might be a placebo effect. While many studies suggest that exercise may have cognitive benefits, those experiments all have had a notable scientific limitation: They have not used placebos. This issue is not some abstruse scientific debate. If the cognitive benefits from exercise are a result of a placebo effect rather than of actual changes in the brain because of the exercise, then those benefits could be ephemeral and unable in the long term to help us remember how to spell ephemeral. © 2014 The New York Times Company
Keyword: Learning & Memory
Link ID: 20329 - Posted: 11.20.2014
By Kelly Servick Dean Hamer finally feels vindicated. More than 20 years ago, in a study that triggered both scientific and cultural controversy, the molecular biologist offered the first direct evidence of a “gay gene,” by identifying a stretch on the X chromosome likely associated with homosexuality. But several subsequent studies called his finding into question. Now the largest independent replication effort so far, looking at 409 pairs of gay brothers, fingers the same region on the X. “When you first find something out of the entire genome, you’re always wondering if it was just by chance,” says Hamer, who asserts that new research “clarifies the matter absolutely.” But not everyone finds the results convincing. And the kind of DNA analysis used, known as a genetic linkage study, has largely been superseded by other techniques. Due to the limitations of this approach, the new work also fails to provide what behavioral geneticists really crave: specific genes that might underlie homosexuality. Few scientists have ventured into this line of research. When the genetics of being gay comes up at scientific meetings, “sometimes even behavioral geneticists kind of wrinkle up their noses,” says Kenneth Kendler, a psychiatric geneticist at Virginia Commonwealth University in Richmond. That’s partially because the science itself is so complex. Studies comparing identical and fraternal twins suggest there is some heritable component to homosexuality, but no one believes that a single gene or genes can make a person gay. Any genetic predispositions probably interact with environmental factors that influence development of a sexual orientation. © 2014 American Association for the Advancement of Science.
By ALAN SCHWARZ CONCORD, Calif. — Every time Matthias is kicked out of a school or day camp for defying adults and clashing with other children, his mother, Joelle Kendle, inches closer to a decision she dreads. With each morning of arm-twisting and leg-flailing as she tries to get him dressed and out the door for first grade, the temptation intensifies. Ms. Kendle is torn over whether to have Matthias, just 6 and already taking the stimulant Adderall for attention deficit hyperactivity disorder, go on a second and more potent medication: the antipsychotic Risperdal. Her dilemma is shared by a steadily rising number of American families who are using multiple psychotropic drugs — stimulants, antipsychotics, antidepressants and others — to temper their children’s troublesome behavior, even though many doctors who mix such medications acknowledge that little is known about the overall benefits and risks for children. In 2012 about one in 54 youngsters ages 6 through 17 covered by private insurance was taking at least two psychotropic medications — a rise of 44 percent in four years, according to Express Scripts, which processes prescriptions for 85 million Americans. Academic studies of children covered by Medicaid have also found higher rates and growth. Combined, the data suggest that about one million children are currently taking various combinations of psychotropics. Risks of antipsychotics alone, for example, are known to include substantial weight gain and diabetes. Stimulants can cause appetite suppression, insomnia and, far more infrequently, hallucinations. Some combinations of medication classes, like antipsychotics and antidepressants, have shown improved benefits (for psychotic depression) but also heightened risks (for heart rhythm disturbances). But this knowledge has been derived substantially from studies in adults — children are rarely studied because of concerns about safety and ethics — leaving many experts worried that the use of multiple psychotropics in youngsters has not been explored fully. There is also debate over whether the United States Food and Drug Administration’s database of patients’ adverse drug reactions reliably monitors the hazards of psychotropic drug combinations, primarily because only a small fraction of cases are ever reported. Some clinicians are left somewhat queasy about relying mostly on anecdotal reports of benefit and harm. © 2014 The New York Times Company
By Emma Wilkinson Health reporter, BBC News Taking vitamin B12 and folic acid supplements does not seem to cut the risk of developing dementia in healthy people, say Dutch researchers. In one of the largest studies to date, there was no difference in memory test scores between those who had taken the supplements for two years and those who were given a placebo. The research was published in the journal Neurology. Alzheimer's Research UK said longer trials were needed to be sure. B vitamins have been linked to Alzheimer's for some years, and scientists know that higher levels of a body chemical called homocysteine can raise the risk of both strokes and dementia. Vitamin B12 and folic acid are both known to lower levels of homocysteine. That, along with studies linking low vitamin B12 and folic acid intake with poor memory, had prompted scientists to view the supplements as a way to ward off dementia. Yet in the study of almost 3,000 people - with an average age of 74 - who took 400 micrograms of folic acid and 500 micrograms of vitamin B12 or a placebo every day, researchers found no evidence of a protective effect. All those taking part in the trial had high blood levels of homocysteine, which did drop more in those taking the supplements. But on four different tests of memory and thinking skills taken at the start and end of the study, there was no beneficial effect of the supplements on performance. The researchers did note that the supplements might slightly slow the rate of decline but concluded the small difference they detected could just have been down to chance. Study leader Dr Rosalie Dhonukshe-Rutten, from Wageningen University in the Netherlands, said: "Since homocysteine levels can be lowered with folic acid and vitamin B12 supplements, the hope has been that taking these vitamins could also reduce the risk of memory loss and Alzheimer's disease. BBC © 2014
Link ID: 20313 - Posted: 11.15.2014
Sara Reardon Companies selling ‘probiotic’ foods have long claimed that cultivating the right gut bacteria can benefit mental well-being, but neuroscientists have generally been sceptical. Now there is hard evidence linking conditions such as autism and depression to the gut’s microbial residents, known as the microbiome. And neuroscientists are taking notice — not just of the clinical implications but also of what the link could mean for experimental design. “The field is going to another level of sophistication,” says Sarkis Mazmanian, a microbiologist at the California Institute of Technology in Pasadena. “Hopefully this will shift this image that there’s too much commercial interest and data from too few labs.” This year, the US National Institute of Mental Health spent more than US$1 million on a new research programme aimed at the microbiome–brain connection. And on 19 November, neuroscientists will present evidence for the link in a symposium at the annual Society for Neuroscience meeting in Washington DC called ‘Gut Microbes and the Brain: Paradigm Shift in Neuroscience’. Although correlations have been noted between the composition of the gut microbiome and behavioural conditions, especially autism1, neuroscientists are only now starting to understand how gut bacteria may influence the brain. The immune system almost certainly plays a part, Mazmanian says, as does the vagus nerve, which connects the brain to the digestive tract. Bacterial waste products can also influence the brain — for example, at least two types of intestinal bacterium produce the neurotransmitter γ-aminobutyric acid (GABA)2. © 2014 Nature Publishing Group
by Helen Thomson Could a futuristic society of humans with the power to control their own biological functions ever become reality? It's not as out there as it sounds, now the technical foundations have been laid. Researchers have created a link between thoughts and cells, allowing people to switch on genes in mice using just their thoughts. "We wanted to be able to use brainwaves to control genes. It's the first time anyone has linked synthetic biology and the mind," says Martin Fussenegger, a bioengineer at ETH Zurich in Basel, Switzerland, who led the team behind the work. They hope to use the technology to help people who are "locked-in" – that is, fully conscious but unable to move or speak – to do things like self-administer pain medication. It might also be able to help people with epilepsy control their seizures. In theory, the technology could be used for non-medical purposes, too. For example, we could give ourselves a hormone burst on demand, much like in the Culture – Iain M. Banks's utopian society, where people are able to secrete hormones and other chemicals to change their mood. Fussenegger's team started by inserting a light-responsive gene into human kidney cells in a dish. The gene is activated, or expressed, when exposed to infrared light. The cells were engineered so that when the gene activated, it caused a cascade of chemical reactions leading to the expression of another gene – the one the team wanted to switch on. © Copyright Reed Business Information Ltd.
By Abby Phillip If you're confused about what marijuana use really does to people who use it, you're not alone. For years, the scientific research on health effects of the drug have been all over the map. Earlier this year, one study suggested that even casual marijuana use could cause changes to the brain. Another found that marijuana use was also associated with poor sperm quality, which could lead to infertility in men. But marijuana advocates point to other research indicating that the drug is far less addictive than other drugs, and some studies have found no relationship between IQ and marijuana use in teens. Researchers at the Center for Brain Health at the University of Texas in Dallas sought to clear up some of the confusion with a study that looked at a relatively large group of marijuana users and evaluated their brains for a slew of different indicators. What they found was complex, but the pattern was clear: The brains of marijuana users were different than those of non-marijuana users. The area of the brain responsible for establishing the reward system that helps us survive and also keeps us motivated was smaller in users than in non-marijuana users. But there was also evidence that the brain compensated for this loss of volume by increasing connectivity and the structural integrity of the brain tissue. Those effects were more pronounced for marijuana users who started young. "The orbitofrontal cortex is one of the primary regions in a network of brain areas called the reward system," explained Francesca Filbey, lead author of the study and an associate professor of the neurogenetics of addictive behavior at the University of Texas in Dallas. "
Email David By David Grimm Place a housecat next to its direct ancestor, the Near Eastern wildcat, and it may take you a minute to spot the difference. They’re about the same size and shape, and, well, they both look like cats. But the wildcat is fierce and feral, whereas the housecat, thanks to nearly 10,000 years of domestication, is tame and adaptable enough to have become the world’s most popular pet. Now scientists have begun to pinpoint the genetic changes that drove this remarkable transformation. The findings, based on the first high-quality sequence of the cat genome, could shed light on how other creatures, even humans, become tame. “This is the closest thing to a smoking gun we’ve ever had,” says Greger Larson, an evolutionary biologist at the University of Oxford in the United Kingdom who has studied the domestication of pigs, dogs, and other animals. “We’re much closer to understanding the nitty-gritty of domestication than we were a decade ago.” Cats first entered human society about 9500 years ago, not long after people first took up farming in the Middle East. Drawn to rodents that had invaded grain stores, wildcats slunk out of the deserts and into villages. There, many scientists suspect, they mostly domesticated themselves, with the friendliest ones able to take advantage of human table scraps and protection. Over thousands of years, cats shrank slightly in size, acquired a panoply of coat colors and patterns, and (largely) shed the antisocial tendencies of their past. Domestic animals from cows to dogs have undergone similar transformations, yet scientists know relatively little about the genes involved. Researchers led by Michael Montague, a postdoc at the Washington University School of Medicine in St. Louis, have now pinpointed some of them. The scientists started with the genome of a domestic cat—a female Abyssinian—that had been published in draft form in 2007, then filled in missing sequences and identified genes. They compared the resulting genome with those of cows, tigers, dogs, and humans. © 2014 American Association for the Advancement of Science.
By Dr. Catherine A. Madison “Now why did I walk into this room? Oh, yes, looking for my …” This scenario, familiar to many, is most often a sign of normal aging — or of having too much on our minds. But when these events seem to be happening frequently, is it a more serious problem, such as Alzheimer’s disease or another dementia? Even more importantly, are there good health habits that can help lower the risk of these neurodegenerative conditions? Research continues to demonstrate that healthy lifestyles lower one’s risk of developing cognitive decline later in life. Wise food choices and lots of exercise are a good base, along with learning new material and keeping socially connected. But another key element to brain health is good sleep. We may take sleep for granted, but research suggests this is not a passive process. There is a growing consensus that sleep is linked to learning, memory, nerve cell remodeling and repair. Evidence also suggests lack of sleep can contribute to mood and immune disorders, as well as to a decline in overall health. Most of us have read the dos and don’ts of good sleep hygiene: avoid napping, don’t drink alcohol or caffeine close to bedtime, avoid late-evening exercise and sleep in a room that is quiet, dark and cool. We’ve also been told about sleep cycles, in which we typically progress from light sleep early in the night to slow wave sleep with rapid eye movement, or REM, later on. We need a balance of sleep cycles for optimal health.
By Tracy Jarrett Autism advocates on Friday applauded Jerry Seinfeld's disclosure that he may be autistic, while warning against making him the poster boy for a disorder that is no laughing matter. “I think, on a very drawn-out scale, I think I’m on the spectrum,” Seinfeld told NBC Nightly News’ Brian Williams. "Basic social engagement is really a struggle. I'm very literal, when people talk to me and they use expressions, sometimes I don't know what they're saying," he said. "But I don't see it as dysfunctional, I just think of it as an alternate mindset." Seinfeld's revelation sends a positive message that the autism community is much larger and more diverse than people often understand, Ari Ne’eman, president of the Autistic Advocacy Network, told NBC News. Ne’eman is living with autism and says that there is still a tremendous amount of stigma surrounding autism that hinders the opportunities available to those with the disorder. “Think about what this does for a closeted autistic person who goes into the workplace knowing that their co-workers have just seen somebody they know, respect, and have a positive opinion of, like Jerry Seinfeld, identify in this way — it’s a valuable and important step in building a greater tolerance for autism,” Ne’eman said. Liz Feld, president of Autism Speaks, agreed, pointing out that “there are many people on the autism spectrum who can relate to Jerry’s heartfelt comments about his own experiences.”
Link ID: 20289 - Posted: 11.08.2014
Sara Reardon Delivering medications to the brain could become easier, thanks to molecules that can escort drugs through the notoriously impervious sheath that separates blood vessels from neurons. In a proof-of-concept study in monkeys, biologists used the system to reduce levels of the protein amyloid-β, which accumulates in the brain plaques associated with Alzheimer's disease1. The blood–brain barrier is a layer of cells lining the inner surface of the capillaries that feed the central nervous system. It is nature's way of protecting the delicate brain from infectious agents and toxic compounds, while letting nutrients and oxygen in and waste products out. Because the barrier strictly regulates the passage of larger molecules and often prevents drug molecules from entering the brain, it has long posed one of the most difficult challenges in developing treatments for brain disorders. Several approaches to bypassing the barrier are being tested, including nanoparticles that are small enough to pass through the barrier's cellular membranes and deliver their payload; catheters that carry a drug directly into the brain; and ultrasound pulses that push microbubbles through the barrier. But no approach has yet found broad therapeutic application. Neurobiologist Ryan Watts and his colleagues at the biotechnology company Genentech in South San Francisco have sought to break through the barrier by exploiting transferrin, a protein that sits on the surface of blood vessels and carries iron into the brain. The team created an antibody with two ends. One end binds loosely to transferrin and uses the protein to transport itself into the brain. And once the antibody is inside, its other end targets an enzyme called β-secretase 1 (BACE1), which produces amyloid-β. Crucially, the antibody binds more tightly to BACE1 than to transferrin, and this pulls it off the blood vessel and into the brain. It locks BACE1 shut and prevents it from making amyloid-β. © 2014 Nature Publishing Group,
Link ID: 20286 - Posted: 11.06.2014
|By Lindsey Konkel and Environmental Health News New York City children exposed in the womb to high levels of pollutants in vehicle exhaust had a five times higher risk of attention problems at age 9, according to research by Columbia University scientists published Wednesday. The study adds to earlier evidence that mothers' exposures to polycyclic aromatic hydrocarbons (PAHs), which are emitted by the burning of fossil fuels and other organic materials, are linked to children's behavioral problems associated with Attention Deficit Hyperactivity Disorder (ADHD). “Our research suggests that environmental factors may be contributing to attention problems in a significant way,” said Frederica Perera, an environmental health scientist at Columbia’s Mailman School of Public Health who was the study's lead author. About one in 10 U.S. kids is diagnosed with ADHD, according to the Centers for Disease Control and Prevention. Children with ADHD are at greater risk of poor academic performance, risky behaviors and lower earnings in adulthood, the researchers wrote. “Air pollution has been linked to adverse effects on attention span, behavior and cognitive functioning in research from around the globe. There is little question that air pollutants may pose a variety of potential health risks to children of all ages, possibly beginning in the womb,” said Dr. Andrew Adesman, chief of developmental and behavioral pediatrics at Steven & Alexandra Cohen Children’s Medical Center of New York. He did not participate in the new study. © 2014 Scientific American
By NICK BILTON Ebola sounds like the stuff of nightmares. Bird flu and SARS also send shivers down my spine. But I’ll tell you what scares me most: artificial intelligence. The first three, with enough resources, humans can stop. The last, which humans are creating, could soon become unstoppable. Before we get into what could possibly go wrong, let me first explain what artificial intelligence is. Actually, skip that. I’ll let someone else explain it: Grab an iPhone and ask Siri about the weather or stocks. Or tell her “I’m drunk.” Her answers are artificially intelligent. Right now these artificially intelligent machines are pretty cute and innocent, but as they are given more power in society, these machines may not take long to spiral out of control. In the beginning, the glitches will be small but eventful. Maybe a rogue computer momentarily derails the stock market, causing billions in damage. Or a driverless car freezes on the highway because a software update goes awry. But the upheavals can escalate quickly and become scarier and even cataclysmic. Imagine how a medical robot, originally programmed to rid cancer, could conclude that the best way to obliterate cancer is to exterminate humans who are genetically prone to the disease. Nick Bostrom, author of the book “Superintelligence,” lays out a number of petrifying doomsday settings. One envisions self-replicating nanobots, which are microscopic robots designed to make copies of themselves. In a positive situation, these bots could fight diseases in the human body or eat radioactive material on the planet. But, Mr. Bostrom says, a “person of malicious intent in possession of this technology might cause the extinction of intelligent life on Earth.” © 2014 The New York Times Company
By James Gallagher Health editor, BBC News website Working antisocial hours can prematurely age the brain and dull intellectual ability, scientists warn. Their study, in the journal Occupational and Environmental Medicine, suggested a decade of shifts aged the brain by more than six years. There was some recovery after people stopped working antisocial shifts, but it took five years to return to normal. Experts say the findings could be important in dementia, as many patients have disrupted sleep. The body's internal clock is designed for us to be active in the day and asleep at night. The damaging effects on the body of working against the body clock, from breast cancer to obesity, are well known. Now a team at the University of Swansea and the University of Toulouse has shown an impact on the mind as well. Three thousand people in France performed tests of memory, speed of thought and wider cognitive ability. The brain naturally declines as we age, but the researchers said working antisocial shifts accelerated the process. Those with more than 10 years of shift work under their belts had the same results as someone six and a half years older. The good news is that when people in the study quit shift work, their brains did recover. Even if it took five years. Dr Philip Tucker, part of the research team in Swansea, told the BBC: "It was quite a substantial decline in brain function, it is likely that when people trying to undertake complex cognitive tasks then they might make more mistakes and slip-ups, maybe one in 100 makes a mistake with a very large consequence, but it's hard to say how big a difference it would make in day-to-day life." BBC © 2014
Kate Baggaley Much of the increase in autism diagnoses in recent decades may be tied to changes in how the condition is reported. Sixty percent of the increase in autism cases in Denmark can be explained by these changes, scientists report November 3 in JAMA Pediatrics. The researchers followed all 677,915 people born in Denmark in 1980 through 1991, monitoring them from birth through the end of 2011. Among children born in this period, diagnoses increased fivefold, until 1 percent of children born in the early 1990s were diagnosed with autism by age 20. During these decades, Denmark experienced two changes in the way autism is reported. In 1994, the criteria physicians rely on to diagnose autism were updated in both the International Classification of Diseases manual used by Denmark and in its American counterpart, the Diagnostic and Statistical Manual of Mental Disorders. Then in 1995, the Danish Psychiatric Register began reporting diagnoses where doctors had only outpatient contact with children, in addition to cases where autism was diagnosed after children had been kept overnight. The researchers estimated Danish children’s likelihood of being diagnosed with autism before and after the two reporting changes. These changes accounted for 60 percent of the increase in diagnoses. © Society for Science & the Public 2000 - 2014.
Link ID: 20280 - Posted: 11.05.2014
By SINDYA N. BHANOO BERKELEY, CALIF. — Lilith Sadil, 12, climbs into an examination chair here at the Myopia Control Center at the University of California. “Do you know why you are here?” asks Dr. Maria Liu, an optometrist. “Because my eyes are changing fast,” Lilith says. “Do you read a lot?” Dr. Liu asks. “Yes.” “Do you use the computer a lot?” “Yes.” Lilith is an active child who practices taekwondo. But like an increasing number of children, she has myopia — she can see close up but not farther away. Her mother, Jinnie Sadil, has brought her to the center because she has heard about a new treatment that could help. Eye specialists are offering young patients special contact lenses worn overnight that correct vision for the next day. Myopia has become something of a minor epidemic: More than 40 percent of Americans are nearsighted, a 16 percent increase since the 1970s. People with so-called high myopia — generally, blurry vision beyond about five inches — face an increased likelihood of developing cataracts and glaucoma, are at higher risk for retinal detachments that can result in blindness. Exactly what is causing the nationwide rise in nearsightedness is not known. “It can’t be entirely genetic, because genes don’t change that fast,” said Susan Vitale, an epidemiologist at the National Institutes of Health who studies myopia. “It’s probably something that’s environmental, or a combination of genetic and environmental factors.” Some research indicates that “near work” — reading, computer work, playing video games, and using tablets and smartphones — is contributing to the increase. A recent study found that the more educated a person is, the more likely he or she will be nearsighted. A number of other studies show that children who spend time outdoors are less likely to develop high myopia. But no one is certain whether the eye benefits from ultraviolet light or whether time outside simply means time away from near work. © 2014 The New York Times Company
Joan Raymond TODAY contributor It’s well established that baby talk plays a huge role in helping the wee widdle babies learn to tawk. And — no surprise — moms talk more to babies than dads do. But it seems that the baby's sex plays a role, too: Moms may be talking more to their infant daughters than their sons during the early weeks and months of a child’s life. In a new study published Monday in the online edition of Pediatrics, researchers looked at the language interactions between 33 late preterm and term infants and their parents by capturing 3,000 hours of recordings. Somewhat surprisingly, the researchers found that moms interacted vocally more with infant daughters rather than sons both at birth and 44 weeks post-menstrual age (equivalent to 1 month old.) Male adults responded more frequently to infant boys than infant girls, but the difference did not reach statistical significance, say the researchers. “We wanted to look more at gender and factors that affect these essentially mini-conversations that parents have with infants,” says lead author and neonatologist Dr. Betty Vohr, director of the Neonatal Follow-Up Program at Women & Infants Hospital of Rhode Island. “Infants are primed to vocalize and have reciprocal interactions.”
By RICHARD A. FRIEDMAN ATTENTION deficit hyperactivity disorder is now the most prevalent psychiatric illness of young people in America, affecting 11 percent of them at some point between the ages of 4 and 17. The rates of both diagnosis and treatment have increased so much in the past decade that you may wonder whether something that affects so many people can really be a disease. And for a good reason. Recent neuroscience research shows that people with A.D.H.D. are actually hard-wired for novelty-seeking — a trait that had, until relatively recently, a distinct evolutionary advantage. Compared with the rest of us, they have sluggish and underfed brain reward circuits, so much of everyday life feels routine and understimulating. To compensate, they are drawn to new and exciting experiences and get famously impatient and restless with the regimented structure that characterizes our modern world. In short, people with A.D.H.D. may not have a disease, so much as a set of behavioral traits that don’t match the expectations of our contemporary culture. From the standpoint of teachers, parents and the world at large, the problem with people with A.D.H.D. looks like a lack of focus and attention and impulsive behavior. But if you have the “illness,” the real problem is that, to your brain, the world that you live in essentially feels not very interesting. One of my patients, a young woman in her early 20s, is prototypical. “I’ve been on Adderall for years to help me focus,” she told me at our first meeting. Before taking Adderall, she found sitting in lectures unendurable and would lose her concentration within minutes. Like many people with A.D.H.D., she hankered for exciting and varied experiences and also resorted to alcohol to relieve boredom. But when something was new and stimulating, she had laserlike focus. I knew that she loved painting and asked her how long she could maintain her interest in her art. “No problem. I can paint for hours at a stretch.” Rewards like sex, money, drugs and novel situations all cause the release of dopamine in the reward circuit of the brain, a region buried deep beneath the cortex. Aside from generating a sense of pleasure, this dopamine signal tells your brain something like, “Pay attention, this is an important experience that is worth remembering.” © 2014 The New York Times Company
Maanvi Singh How does a sunset work? We love to look at one, but Jolanda Blackwell wanted her eighth-graders to really think about it, to wonder and question. So Blackwell, who teaches science at Oliver Wendell Holmes Junior High in Davis, Calif., had her students watch a video of a sunset on YouTube as part of a physics lesson on motion. "I asked them: 'So what's moving? And why?' " Blackwell says. The students had a lot of ideas. Some thought the sun was moving; others, of course, knew that a sunset is the result of the Earth spinning around on its axis. Once she got the discussion going, the questions came rapid-fire. "My biggest challenge usually is trying to keep them patient," she says. "They just have so many burning questions." Students asking questions and then exploring the answers. That's something any good teacher lives for. And at the heart of it all is curiosity. Blackwell, like many others teachers, understands that when kids are curious, they're much more likely to stay engaged. But why? What, exactly, is curiosity and how does it work? A study published in the October issue of the journal Neuron suggests that the brain's chemistry changes when we become curious, helping us better learn and retain information. © 2014 NPR
By CATHERINE SAINT LOUIS More than 50 children in 23 states have had mysterious episodes of paralysis to their arms or legs, according to data gathered by the Centers for Disease Control and Prevention. The cause is not known, although some doctors suspect the cases may be linked to infection with enterovirus 68, a respiratory virus that has sickened thousands of children in recent months. Concerned by a cluster of cases in Colorado, the C.D.C. last month asked doctors and state health officials nationwide to begin compiling detailed reports about cases of unusual limb weakness in children. Experts convened by the agency plan next week to release interim guidelines on managing the condition. That so many children have had full or partial paralysis in a short period is unusual, but officials said that the cases seemed to be extremely rare. “At the moment, it looks like whatever the chances are of getting this syndrome are less than one in a million,” said Mark A. Pallansch, the director of the division of viral diseases at the C.D.C. Some of the affected children have lost the use of a leg or an arm, and are having physical therapy to keep their muscles conditioned. Others have sustained more extensive damage and require help breathing. Marie, who asked to be identified by her middle name to protect her family’s privacy, said her 4-year-old son used to climb jungle gyms. But in late September, after the whole family had been sick with a respiratory illness, he started having trouble climbing onto the couch. He walked into Boston Children’s Hospital the day he was admitted. But soon his neck grew so weak, it “flopped completely back like he was a newborn,” Marie said. Typically, the time from when weakness begins until it reaches its worst is one to three days. But for her son, eight mornings in a row, he awoke with a "brand new deficit" until he had some degree of weakness in each limb and had trouble breathing. He was eventually transferred to a Spaulding rehabilitation center, where he is now. © 2014 The New York Times Company